/**HEADER********************************************************************
* 
* Copyright (c) 2008 Freescale Semiconductor;
* All Rights Reserved
*
* Copyright (c) 2004-2008 Embedded Access Inc.;
* All Rights Reserved
*
* Copyright (c) 1989-2008 ARC International;
* All Rights Reserved
*
*************************************************************************** 
*
* THIS SOFTWARE IS PROVIDED BY FREESCALE "AS IS" AND ANY EXPRESSED OR 
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  
* IN NO EVENT SHALL FREESCALE OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 
* THE POSSIBILITY OF SUCH DAMAGE.
*
**************************************************************************
*
* $FileName: lws_wait.c$
* $Version : 3.8.6.0$
* $Date    : Aug-30-2011$
*
* Comments:
*
*   This file contains the functions for manipulating the 
*   light weight semaphores.  These semaphores have low memory
*   requirements, and no extra features.  Tasks are suspended
*   in fifo order while waiting for a post.  No limits on values
*   are imposed.
*
*END************************************************************************/

#include "mqx_inc.h"

/*FUNCTION*-------------------------------------------------------------------
* 
* Function Name    : _lwsem_wait
* Returned Value   : an error code
*   queue
* Comments         :
*   This function obtains a semaphore from the lwsem.  If one is not
* available, the task waits (in a FIFO order)
*
*END*----------------------------------------------------------------------*/

_mqx_uint _lwsem_wait
   (
      /* [IN] the semaphore address */
      LWSEM_STRUCT_PTR sem_ptr
   )
{ /* Body */
    KERNEL_DATA_STRUCT_PTR kernel_data;
    TD_STRUCT_PTR          td_ptr;
   
#if MQX_ENABLE_USER_MODE && MQX_ENABLE_USER_STDAPI
    if (MQX_RUN_IN_USER_MODE) {
        return _usr_lwsem_wait(sem_ptr);
    }
#endif

    _GET_KERNEL_DATA(kernel_data);

    _KLOGE2(KLOG_lwsem_wait, sem_ptr);

#if MQX_CHECK_ERRORS
    if (kernel_data->IN_ISR) {
        _KLOGX2(KLOG_lwsem_wait, MQX_CANNOT_CALL_FUNCTION_FROM_ISR);
        return(MQX_CANNOT_CALL_FUNCTION_FROM_ISR);
    }
#endif
    
#if MQX_CHECK_VALIDITY
    if (sem_ptr->VALID != LWSEM_VALID) {
        _KLOGX2(KLOG_lwsem_wait, MQX_INVALID_LWSEM);
        return(MQX_INVALID_LWSEM);
    }
#endif

    _INT_DISABLE();
    if (sem_ptr->VALUE <= 0) {
        td_ptr = kernel_data->ACTIVE_PTR;
        td_ptr->STATE = LWSEM_BLOCKED;
        td_ptr->INFO  = (_mqx_uint)&sem_ptr->TD_QUEUE;
        _QUEUE_UNLINK(td_ptr);
        _QUEUE_ENQUEUE(&sem_ptr->TD_QUEUE, &td_ptr->AUX_QUEUE);
        _sched_execute_scheduler_internal();  /* Let the other tasks run */
        /* Another task has posted a semaphore, and it has been tranfered to this 
        ** task.
        */
    } else {
        --sem_ptr->VALUE;
    }

//#if MQX_COMPONENT_DESTRUCTION
    /* We must check for component destruction */
    if (sem_ptr->VALID != LWSEM_VALID) {
        _int_enable();
        /* The semaphore has been deleted */
        _KLOGX2(KLOG_lwsem_wait, MQX_INVALID_LWSEM);
        return(MQX_INVALID_LWSEM);
    } /* Endif */
//#endif

    _INT_ENABLE();

    _KLOGX2(KLOG_lwsem_wait, MQX_OK);

    return(MQX_OK);
}

/*FUNCTION*-------------------------------------------------------------------
* 
* Function Name    : _usr_lwsem_wait
* Returned Value   : an error code
*   queue
* Comments         :
*   This function obtains a semaphore from the lwsem.  If one is not
* available, the task waits (in a FIFO order)
*
*END*----------------------------------------------------------------------*/

#if MQX_ENABLE_USER_MODE

_mqx_uint _usr_lwsem_wait
   (
      /* [IN] the semaphore address */
      LWSEM_STRUCT_PTR sem_ptr
   )
{
    MQX_API_CALL_PARAMS params = {(uint_32)sem_ptr, 0, 0, 0, 0};
    return _mqx_api_call(MQX_API_LWSEM_WAIT, &params);
}

#endif /* MQX_ENABLE_USER_MODE */
